Unira

Unira (known as Sea Urchins in localized versions of Clu Clu Land) are a type of sea urchin serving as the main antagonists of Clu Clu Land. In the game, they have taken all of Clu Clu Land's gold bars and try to stop the game's protagonist, Bubbles, from getting them back.

Unira later appear as items in Super Smash Bros. Brawl and Super Smash Bros. for Nintendo 3DS / Wii U, which refers to them under their Japanese name. Unira can be picked up and tossed at opposing players. After being thrown, its spikes pop out damaging all except the one who threw it. When players stand close enough to it, it draws them toward itself. An Unira can change "possession", so to speak, if it is attacked. For example, if a player throws it, the Unira will not harm the player; however, if an opponent attacks the Unira, its properties will change and cause harm to the player while not damaging the opponent.

In Clu Clu Land, the Unira hid gold ingots in an underwater maze, then tried to stop Bubbles from getting them. In Super Smash Bros. Brawl, you can attack an Unira to send it bouncing away. Any fighter it hits will go sprawling. If it hits a wall, it'll bounce back, and if you hit it with a powerful attack, it will transfer the attack to whomever it hits and launch them.

What a cute little creature! You just want to... Oh, wait–those spikes aren't just for show! Once thrown or attacked, its spikes extend out and hurt anyone but the character who threw it. Attacking it again can make the spikes retract, so you could even throw it back at the original owner.